A DAC and its connected input signal components require ultra-low noise power for best sound. This cannot be overstated. For DACs with a direct DC input, avoid the factory provided (external brick) switch-mode supply and rather use one with a better regulation/filtering design. Battery-based power supplies are better but even they may generate RF noise from buck-type voltage regulators, digital logic modules or integrated switch-mode AC inverters. Consider a simple LiFePO₄ (LFP) battery for the lowest electrochemical discharge noise and use voltage compatible components.
RF•STOP™ DC Power Filter ensures even the best power supplies are properly RF noise filtered. Power supplies with upgraded fuses or improved wiring offer only a nominal level of additional RF filtering. RF•STOP uses a two-stage design with inductors of highly permeable core material for excellent attenuation of common-mode and normal-mode noise. RF•STOP's wideband filtering extends up to the critical RF frequency of 500MHz and DC rating of 3V to 30V @ 4A is sufficient for all DACs and components.
RF•STOP also helps with noise isolation between components that are powered by the same DC power supply (via a splitter cable). Installing RF•STOP DC Filter between the power supply and component prevents transfer of RF noise between components. Use 2.1mm connections for input and output and a well shielded DC power cable such as Gotham GAC-4/1 11301 UltraPro Star Quad available from Ghent Audio. For maximum isolation from EMF induced noise via cable antenna effects, locate RF•STOP DC Filter close to the component and use an ultra-short DC power cable (0.3 meter or 12 inches is ideal).